2009 年 55 巻 2 号 p. 161-165
Sods of 6 legume species established in autumn were mowed 1-3 times by late May, and then 'Tentaka' forage sorghum cultivar (Sorghum bicolor (L.) Moench) was striptill planted with no nitrogen and no herbicide application. Though weeds were severely depressed by all legume sod, the dry matter yields of sorghum varied with sod species. The sods of white clover (Trifolium repens L.), crimson clover (Trifolium incarnatum L.) and Chinese milk vetch (Astragalus sinicus L.) produced high sorghum DM yields of 14-16t ha^<-1>. These yields did not differ from those of tillage with 100kgN ha^<-1> and were 2-3 times higher than those from tillage with no nitrogen. Red clover (Trifolium pratense L.) caused a sorghum growth depression due to interference by the regrown sod. In consequence, the density of sorghum at harvest decreased by 60% of the initial value, which resulted in much lower yield than those from the other 5 legumes.